Monitoring of tunnel lining deformation and deterioration Prof. Ivan Vaníček, DSc. Martin Vaníček, PhD. & Jan Záleský, CSc. Geotechnical Department Faculty of Civil Engineering Czech Czech Republic
Why to monitor tunnel lining Ageing optimum timing for the maintenance / repair (Design life 70 120 years, Service life could be longer with proper p maintenance) Building activity surface & subsurface Accidents / Hazards terrorist attacks, floods (as in Prague), earthquakes To investigate innovative methods of measurement 2
Types of Monitoring for tunnel lining ageing Whole profile Conventional monitoring Convergence measurements Innovative monitoring Computer vision based Local monitoring Conventional monitoring Tilting measurements Innovative monitoring Geophysical monitoring Lining vibration response on train passing Crack & micro-crack crack development Conventional monitoring Crackmeter measurements Innovative monitoring Micro-strain i MEMS (Micro Electrical l Mechanical Sensor) based Geophysical monitoring Longer section of metro tunnel Innovative monitoring 3D Laser scanning Computer vision based 3
Precision of measurements Conventional measurements Convergence measurements Sensitivity 0.01 mm Repeatability 0.05 mm Tiltmeter measurements Sensitivity 0.04 mm/m Crackmeter measurements Sensitivity 0.0125 mm Cr.14 287 Cr.14 284 4
Precision of measurements Innovative measurements Micro-strain MEMS Sensitivity 1 10-4 mm (still under investigation) Computer vision Sensitivity up to 0.1 mm 3D laser scanning Sensitivity 1-3 mm Geophysical Results are extremely sensitive but unit less 5
Results of deformation measurements Day 105 Crack Monitoring 0,02 1. Proved that changes in 0,01 deformations in time are 0-0,01 within measuring tolerances -0,02-0,03 metro is in a good shape -0,04-0,06 2. Deformations are very -0,07 sensitive to temperature Time [hh:mm] and moisture changes Crackmeter 14 287: Crack Crackmeter 14 284: Reference Temperature of the sensor Cha ange of deformation [m mm] 0,03-0,05 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 20 19 18 17 16 15 14 13 12 11 10 [ C] Temp perature of the sensor Chan nge of inclinatio on [mm/m] 1,00 0,50 0,00-0,50-1,00-1,50 01/12/06 01/02/07 01/04/07 01/06/07 01/08/07 01/10/07 01/12/07 01/02/08 01/04/08 01/06/08 25,0 20,0 15,0 10,0 5,0 0,0 ining [ C] Temp perature of the l Plate 2.02 Plate 2.03 Temperature of the lining 6
Geophysical monitoring Proved even for short period of monitoring that there are invisible deteriorations in concrete lining 7
Data collection in tunnel Direct measurements Collection from datalogers Wired collection into station Wireless data collection and transfer This option is the optimum one as the data arrive immediately on the controllers PC GPRS Station BALLOON (Linux Computer) Ethernet SENSOR SECTION X 1 GATEWAY Hopping Trial 30m 100m 170m 8
Thank you for your attention Acknowledgement: To all cooperative partners of the ESF Underground M 3 project: - Cambridge University - Universidad Politécnica de Catalunya - Consiglio Nazionale delle Ricerche Bologna Czech Technical University was supported by Grant Agency of the Czech Republic - project No 103/09/1600 /